As a service point with independent functions, an SMS system generally accesses a PLMN (Public Land Mobile Network) via an STP (Signaling Transfer Point) to realize SMS application and provide carriers with short message service and its abundant value-added services.
Generally, a typical networking for SMS is as follows: an SMSC (Short Message Service Center) shields its interaction with a PLMN through a GIW (Gateway-Interworking), while the GIW accesses the PLMN via an STP. The networking for SMS may include a plurality of SMS systems, each of which includes an SMSC and a GIW. In the mobile network, the SMS systems are independent with each other and each SMS system has its own subscribers. Thus, once one of these systems fails, the SMS provided by it will be interrupted and become unavailable for its respective subscribers.
With the development of SMS and the popularization of mobile subscribers, the traffic of short messages increases accordingly, which presents higher requirement for disaster recovery backup and high reliability of an SMS system, requires the SMS system to have the capability of self-adaptation so as to react with the operating condition of the system and provide short message service uninterruptedly and stably as much as possible.
In view of the above situations, Chinese patent application publication No. CN 1453979A discloses an applicable technical solution in which individual SMS systems in a networking for SMS have backup relation with each other to compensate for the insufficiency of disaster recovery capability of a single system, thereby the reliability of SMS is improved.
FIG. 1 is a diagram showing the architecture of a networking for SMS disclosed in the patent application. As shown in FIG. 1, the networking includes three SMS systems, i.e. GIW1+SMSC1, GIW2+SMSC2 and GIW3+SMSC3, wherein the first and the second SMS systems are connected with each other so that backup relation exists between the two systems. If the GIW1 fails, an STP can transfer messages sent to the GIW1 originally to the GIW2; if the predetermined SMSC2 fails, the GIW2 can transfer messages to the SMSC1 to be processed so as to maintain uninterrupted operation of SMS.
Signaling level disaster recovery and system level disaster recovery of an SMS system can be achieved by the technical solution disclosed in the patent application. Taking the example of submitting short messages, put briefly, the flow path of the short messages is →STP→GIW→SMSC, and if the STP detects that the GIW of a certain SMS system fails, then it shunts the messages to the GIW of a backup SMS system by utilizing a global code address transforming function of the STP, thereby signaling level disaster recovery is achieved. The other is system level disaster recovery, for example, in FIG. 1, the SMSC2 is the backup SMSC of the SMSC1, if the GIW1 detects that the SMSC1 fails, then the GIW1 can shunt the messages to the SMSC2. The flow path of delivering short messages is →SMSC→GIW→STP, the processing of signaling level disaster recovery and system level disaster recovery based on the delivery of short messages is similar to that of submitting short messages, therefore the description thereof will be omitted.
But the shunting processing for short messages in the GIW/SMSC is excessively simple. The detailed analysis is as follows:
When short messages are shunted to other GIWs/SMSCs, all the message traffic can only be allocated uniformly regardless of the current load support condition of these GIWs/SMSCs. For example, in FIG. 1, when the GIW2 shunts short messages to the SMSC1, the load condition of the SMSC1 is not taken into consideration. Because the GIW2 is not connected with the SMSC3 in the networking and can not utilize the available processing capacity of the SMSC3 in the networking, the GIW2 can not adjust traffic allocation among individual SMSCs in the networking when shunting. Even if the GIW2 is connected with the SMSC3 and can shunt short messages to the SMSC3, how to balance the traffic allocation between the SMSC1 and the SMSC3, and how to consider the effect of the traffic from the GIW3 to the SMSC3, etc. are not mentioned in the solution.
Thus, the object of disaster recovery can be achieved only by establishing backup relation from the point of view of redundancy in the conventional SMS system, and only the established backup SMS system can be used for redundancy backup. Further, the traffic can not be adjusted according to the actual operating load of individual SMS systems in the current networking. Conventionally, messages are entirely transferred to a backup system regardless of the load of the backup system, which increases the possibility of impacting the backup system while achieving disaster recovery.